Indian Stamp Act, 1899
16. Denoting duty
Where the duty with which an instrument is chargeable, or its
exemption from duty, depends in any manner upon the duty actually paid in
respect of both the instruments, be denoted upon such first mentioned
instrument by application is made in writing to the Collector for that purpose,
and on production of both the instruments, be denoted upon such first mentioned
instrument by endorsement under the hand of the Collector or in such other
manner (if any) as the 6[State Government] may by rule prescribe.